352
FXUS65 KPIH 172308
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
508 PM MDT Fri Oct 17 2025

.KEY MESSAGES...

- Predominantly dry weather expected into late Saturday, though
  a few light snow showers will be possible Island Park to
  Driggs tonight.

- Warm Sunday with 60s returning for some areas!

- A fast-moving, generally low-impact system is expected to
  bring light rain and snow showers, along with breezy
  conditions, Sunday into portions of Monday. This system has
  been trending a bit drier in model guidance.

&&

.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 117 PM MDT Fri Oct 17 2025

Satellite imagery shows mid and high clouds shifting southeast
across East Idaho today on northwest flow. Low clouds and
pockets of fog from earlier this morning have mostly dissipated
per observation and area web cams. Next upstream shortwave
feature currently shifting toward Idaho panhandle per satellite
imagery expected to shift southeast through Montana overnight
into early Saturday. A few showers remain possible mainly across
the Island Park and Yellowstone regions. High end precipitation
estimates bring the showers as far south as the Teton Valley and
the Big Hole Mountains late tonight. QPF amounts remain very
light, with even high-end estimates holding around 0.10" liquid.
Confidence is low that the showers will be more than isolated
and more than a couple hundredths. Overnight lows in these
areas will be below freezing, so the precipitation will fall at
snow even down to valley floors through the Island Park and
Teton Valley regions. The rest of the region will remain dry.
Generally dry conditions are forecast for Saturday and Saturday
night after the system works through. After daytime high
temperatures very similar to today, southerly winds start to
increase during the overnight in response to the system arriving
Sunday. Downslope flow across southern portions of the region
will help to elevate overnight lows in some areas, but many
areas across the north will remain below freezing for Saturday
night.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 117 PM MDT Fri Oct 17 2025

We are expecting a quick hitting Sunday and Sunday night. For
lower elevations, the bigger impacts may come from wind. It
isn`t look strong enough for any type of headlines, but
certainly should be pretty gusty out there. The bulk of the
moisture falls in the Sawtooths and surrounding ranges, as well
as the eastern highlands. The latest precipitation totals add
quite a bit in the Sawtooths/Stanley area, and pushes amounts
into the 0.25-0.50" range. That is actually pushing the top end
of the probability forecasts from WPC and Blend of Models. For
the eastern highlands, we are looking at 0.15-0.40" officially.
The high end of the probability forecasts is double that, while
the low end shows barely a tenth of an inch along the Wyoming
border. Given how quickly this storm is moving through, we can
see where the official forecast comes down a bit, but still some
decent moisture headed our way. We are expecting a pretty
decent break until the end of next week. Our Blend of Models
wants to bring in precipitation Friday over western portions of
our forecast area, but it may indeed hold off until later in the
weekend. After seeing highs dip back down into the 50s where
most of the population lives, we will be back into the 60s ahead
of next weekend`s storm.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 507 PM MDT Fri Oct 17 2025

It will remain a bit breezy through this evening and early
tonight, but winds will be diminishing for Saturday. Overall,
VFR conditions are expected at all sites. The one thing we will
need to watch tonight is the development of some patchy dense
fog again. The chance seems lower tonight, closer to a 10
percent chance at IDA and PIH. Saturday is shaping up to be
another day of VFR conditions even as a weak shortwave clips
northeastern Idaho as any precipitation it brings looks to stay
north of our TAF sites for now.

&&

.FIRE WEATHER...
Issued at 335 AM MDT Fri Oct 17 2025

A break between storm systems will support mostly dry conditions
today and Saturday. One progressive shortwave trough will brush
across our forecast area from the north tonight...just enough
to bring slightly breezier conditions especially at higher
elevations of the Central Mountains and MT border, as well as
perhaps a couple stray rain/snow showers northeast of Rexburg in
areas like Island Park and Driggs. No major impacts are
expected. Our next storm system...a larger progressive
shortwave trough...will bring light rain and snow showers along
with increased winds Sunday into a decent chunk of Monday. This
system has been trending a bit drier in model guidance, but
winds have been trending slightly stronger focused especially on
Sunday afternoon and Sunday night. The best chance of wetting
rain/snow will be in Zone 475 as well as northern Zone 422.

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

SHORT TERM...DMH
LONG TERM...Keyes
AVIATION...AMM
FIRE WEATHER...01